This question appears to be off-topic because it is about the user is asking for a list that may not be complete, hence it is unlikely that an answer is found that is satisfying.
– cdeckerSep 14 '13 at 19:02

10 Answers
10

jzgarzik wrote a very basic miner in Python. It is slow on purpose, because it shows how a simple miner works (and the mining process). It can also be reused as boilerplate code (the getwork JSON-RPC command).

The official list is on The Wiki and is constantly being modified since new software shows up fairly often, but here's the quick breakdown:

Poclbm - Python/OpenCL GPU miner (GUI)

DiabloMiner - Java/OpenCL GPU miner (MAC OS X GUI)

RPC Miner - remote RPC miner (MAC OS X GUI)

Phoenix miner - miner

Cpu Miner - miner

Ufasoft miner - miner

Pyminer - Python miner, reference implementation

Remote miner - mining pool software

Open Source FGPA Bitcoin Miner - a miner that makes use of an FPGA Board

Poclbm and Phoenix are probably the most popular (links go to the sources) though that's based more on my opinion than any facts or studies. In either case, both should shed some light on the mining process.

The source code is well written and shows quite clearly the way that hashing is performed in order to mine new blocks. It is however a CPU-only algorithm, and doesn't use some of the more advanced mechanisms for accelerating the hashing process.

Despite this, it definitely offers a good introduction into how the generation of blocks, hashing etc. works, without the added overhead of having to deal with potentially unfamiliar GPU-based mining code, which is intentially highly optimised and as a result will likely to be more difficult to understand, and make the basic concepts more difficult to follow.